Enhanced nonlinear absorption and efficient optical limiting action of a few 1,3,4-oxadiazole-based donor-acceptor systems

Three new pi-conjugated donor-acceptor (D-A) systems holding cyanoacrylic acid unit as common acceptor and tunable (10-octyl-7-(5-aryl-1,3,4-oxadiazol-2-yl)-10H-phenothiazines as donor components were synthesized under mild, transition metal-free conditions. Photophysical, electrochemical, optical and thermal properties of the D-A systems were examined. HOMO and LUMO of these D-A systems were mapped on the basis of computational studies. All the three compounds displayed good fluorescence quantum yields. Third order nonlinear optical properties of these compounds were also investigated by Z-scan technique using 532 nm, 7 ns laser pulses and it was found that all the compounds exhibit good reverse saturable absorption behaviour. Optical limiting studies of the compounds reveal their ability to limit intense light with promising limiting threshold values (0.69, 0.91 and 1.18 J/cm(2)) comparable with many of the benchmark results reported, alluding their potential to act as good optical limiters.

Automated summary

Three new pi-conjugated donor-acceptor systems with good fluorescence properties and reverse saturable absorption behavior were synthesized, showing potential as optical limiters.